Chapter 7: Sauces
Introduction
Flour based sauces
1. Espagnole
2. Velouté
3. Béchamel
Emulsion based sauces
1. Hollandaise
2. Béarnaise
3. Mayonnaise
Flour based sauces
- Thickening of flour-based sauces is induced by amylose & amylopectin which are present in
the flour in the starch granules
- Starch granules: 2-100 μm
o Ratio of amylose and amylopectin in the granules is dependent on the type of plant
and growth conditions
- Amylose and amylopectin are very large and experience each other to a large extent,
thereby increasing the viscosity of the solution
Increasing temperature in excess of water and under stirring
- Below melting point/gelatinization temperature (60-70 degrees): granules swelling, amylose
leaching from granules. Starch granules become more transparent.
- 80-90 degrees: melting/gelatinization, more amylose leaching. Temperature where most of
the thickening will occur.
o Amylose leaching will form long and stiff chains with other amylose molecules,
single or multiple helices stabilized by hydrogen bonding
o It is the length of these chains that make it efficient for thickening
- More swelling, complete leaching
- Disruption of the granules
- Due to its branched morphology amylopectin does not contribute significantly to the
thickening
Gelatinization of different types of starch
- Different types of starch thicken in different ways
- Thickening mechanism of starch granules: described above
- Thickening mechanism of cross-linked starch: Cross-linked starch granules do not
disintegrate when heated instead the thickness is given by the presence of these particles
that have a certain stiffness into the system
o Hydrophobic chemically modified starch can stabilize emulsions
o Degraded by salivary amylase in the mouth
o This results in coalescence of the oil droplets in the mouth which give a creamy
taste/perception
o Catch 22
Introduction
Flour based sauces
1. Espagnole
2. Velouté
3. Béchamel
Emulsion based sauces
1. Hollandaise
2. Béarnaise
3. Mayonnaise
Flour based sauces
- Thickening of flour-based sauces is induced by amylose & amylopectin which are present in
the flour in the starch granules
- Starch granules: 2-100 μm
o Ratio of amylose and amylopectin in the granules is dependent on the type of plant
and growth conditions
- Amylose and amylopectin are very large and experience each other to a large extent,
thereby increasing the viscosity of the solution
Increasing temperature in excess of water and under stirring
- Below melting point/gelatinization temperature (60-70 degrees): granules swelling, amylose
leaching from granules. Starch granules become more transparent.
- 80-90 degrees: melting/gelatinization, more amylose leaching. Temperature where most of
the thickening will occur.
o Amylose leaching will form long and stiff chains with other amylose molecules,
single or multiple helices stabilized by hydrogen bonding
o It is the length of these chains that make it efficient for thickening
- More swelling, complete leaching
- Disruption of the granules
- Due to its branched morphology amylopectin does not contribute significantly to the
thickening
Gelatinization of different types of starch
- Different types of starch thicken in different ways
- Thickening mechanism of starch granules: described above
- Thickening mechanism of cross-linked starch: Cross-linked starch granules do not
disintegrate when heated instead the thickness is given by the presence of these particles
that have a certain stiffness into the system
o Hydrophobic chemically modified starch can stabilize emulsions
o Degraded by salivary amylase in the mouth
o This results in coalescence of the oil droplets in the mouth which give a creamy
taste/perception
o Catch 22
